Polars and Density of Air

[rgleason]

Here is a better image for the calcs. I hope. Darn not totated.

[TeddyDiver]

To all other directions except dw the weight of air is irrelevant. It's the pressure gradient around the sail and there's no fluid weight in that formula...

Just saying

[Snowpetrel]

Rho is used as density. It looks to me from the above formula that if everything else is the same lift is proportional to density.

Makes sense to me, a simple example is that a rudder has far more lift in water than it does in air. Probably close to proportional to the change in density.

[StuM]

Originally Posted by TeddyDiver

To all other directions except dw the weight of air is irrelevant. It's the pressure gradient around the sail and there's no fluid weight in that formula...

Just saying

Tell that to a helicopter or prop driven fixed wing pilot who tries to fly at very high altitude

[TeddyDiver]

Originally Posted by StuM

Tell that to a helicopter or prop driven fixed wing pilot who tries to fly at very high altitude

In a different Froude number are they among other things..

[rgleason]

Please back up this statement with facts, or fully explained equations. Otherwise we have no reason to believe this. Thank you. - Or alternatively, prove the previous equations incorrect. You will be trying to refute UTC engineers, in so doing!

[rgleason]

Please see this discussion
Dochead provides a good density of air calculator too.

http://www.cruisersforum.com/forums/...d.php?t=190157